砸牌子

zápáizi ㄗㄚˊ ㄆㄞˊ ˙ㄗ

    • to ruin the good name of a shop or brand
    • to damage a reputation

Character by character

Saying俗语俗語

Idiom惯用语 · Widely known

Literally
to smash the signboard
Meaning
To ruin a good name or reputation, as of a shop or brand.

Sources